According to She Knows, "Tatiana" is the feminine form of Tatius, which is a Roman family name or clan name. The masculine version has an unknown meaning according to Behind the Name, but it comes from King Titus Tatius.
Another masculine form of Tatiana is Tatianus. Feminine variants of the name include Tatyana and Tanya in Russian, Tatjana in Finnish and German, and Tiana or Tianna in English. Tatiana is also the name of a third-century Orthodox Christian saint who died as a martyr in Rome. The name became popular in the 1980s in the United States and is still common in 2014.